When it comes to their core business companies have a decent belief in what it looks like.
Playing a little bit the devil's advocate here:
Risk aversion and general tendency to apply gradual changes.
Would you bet your company to run an experiment almost no one else is trying? Perhaps letting your workers work from home works perhaps you'll miss all deadlines and generate all kinds of drama.
An external factors kicked in and everyone was in the same experiment. Things were messy but not completely unmanageable. Some were even surprised things kept working as well as they did.
Now, the big question is: will this take a toll on people? Will companies that choose to continue with this work style be put in disadvantage as other companies switch back to on-prem?
Because it seemed impossible, until now.
That would make the ones doing the firing redundant too. You want as many employees as possible as cheap as possible.